Many modern buildings and products utilize interconnected pipes, tubes and rod. Buildings frequently use metal tubes to form handrails, bicycle racks and other fixtures. These handrails are formed by a variety of different diameter tubes as shown in FIG. 1 of U.S. Pat. No. 6,435,783. The end of one tube is joined to the sidewall of another. The ends of the tubes are notched to form a smooth joint where one tube is welded or otherwise secured to another. Chemical and food processing plants incorporate elaborate metal and PVC piping systems to efficiently move and dispense fluids throughout the plant as shown in FIG. 2 of U.S. Pat. No. 6,435,783. One pipe or tube can have a hole drilled in its sidewall, with another pipe or tube being angled so that the fluid in the pipe will smoothly flow into the other. The end of the pipe is notched to flushly mate against the sidewall of the other to help achieve this smooth fluid flow. Manufacturing plants produce a wide variety of consumer products formed from interconnected tubes, such as lawn furniture, play ground equipment, bicycle and motor cycle frames, automobile chassis, airplane fuselages, exhaust manifolds, scaffolding and crane booms.
To assemble these building fixtures, piping systems and consumer products, a number of tubes, pipes, rods or other types of workpieces are cut to their appropriate length, and if necessary, bent into a desired shape. A notching machine is then used to cut or otherwise form a notch into one or both ends of each workpiece. These workpieces or component parts are then assembled to form the desired product. The notched end of one part smoothly mates with and is welded or otherwise joined to the sidewall of another part to form an integral fixture, pipe system or product. A variety of notching machines are used to form notches in plastic and metal pipes, tubes and rods. Two types of notching machine are the higher end drill bit type notching machines such as shown in U.S. Pat. No. 6,435,783 and the more economical hole saw tube notchers shown in U.S. Pat. No. 7,607,870, the contents of which are incorporated by reference. These types of notchers include a conventional vice with a stationary plate and a parallel moving plate to hold the workpiece. The stationary plate can take the form of a V-shape to help align the workpiece with the hole saw.
One problem with conventional hole saw notchers is properly aligning a workpiece. When the conventional or V-notch vice is gripping the workpiece, the vice does not align the workpiece centerline with the axis of rotation of the hole saw. The operator must make complicated calculations to properly align the workpiece with the hole saw, or rely on guess work, both of which result in malformed notches, and excessive and costly rework time and scrap.
Another problem with conventional hole saw tube notchers is forming a notch when the hole saw is too short. The length of a given a hole saw may be too short to pass completely through a workpiece, particularly for larger diameter workpieces. When this occurs, the operator must position the workpiece once to from a first partial notch in the workpiece. Then, rotate and realign the workpiece to cut through the opposite side of the workpiece to complete the notch. Not only is this time consuming, the need to reposition or realign the workpiece results in misalignment that produces a abnormality in the finished notch.
A further problem with conventional hole saw tube notchers is their inefficiency forming a multi-angled notch. Again, the operator has to reposition or realign the workpiece for each notch portion of the multi-angled notch.
A still further problem with conventional hole saw tube notchers is their inefficiency when the diameter of the workpiece or hole saw changes. For notching machines using a conventional fixed plate vice, each time a different diameter hole saw is used, the operator has to realign the workpiece with hole saw. The same situation arises each time a different diameter workpiece is secured to the notcher. Yet, a single handrail, piping system, or product may require a variety of different diameter tubes, pipes or rods that must be notched to suit a particular joint geometry. This problem is compounded by the fact that construction sites and manufacturing plants frequently have several different projects or product runs going simultaneously. One project may require several different tube diameters, notch sizes and shapes, and each notch may need to be finished by a grinding or polishing tool. Every time the diameter of the workpiece or hole saw changes, the operator must figure out the proper alignment of the workpiece with the hole saw.
A still further problem with conventional hole saw tube notchers is their inability or inefficiency in forming offset notches. Some less expensive notcher do not provide this feature, and other notchers require time consuming adjustment to produce an offset notch.
A still further problem with conventional hole saw tube notchers is their inability to rework a notch of a workpiece to achieve a better fit with a given structure. Notwithstanding the guesswork frequently used with conventional tube notchers, particularly for angled notches, these notchers tend to decreases the centerline length of the workpiece when reworking the notch, which prevents a quality fit, unattractive appearance, and may even reduce the strength of the finished structure.
A still further problem with conventional hole saw tube notchers is their bulky, heavy and awkward to pick up designs that render them difficult to transport.
The present invention is intended to solve these and other problems.